In a major victory for murder suspect George Zimmerman, a judge Saturday ruled that prosecutors may not put on the witness stand two state audio experts who say the voice heard screaming for help on a 911 call was someone other than Zimmerman.

Those screams, recorded while Zimmerman was fighting with 17-year-old Trayvon Martin, are the most dramatic piece of evidence in the high-profile murder case.

Zimmerman, a former Neighborhood Watch volunteer, says they came from him, that he was calling for help after Trayvon attacked him. Trayvon's parents say they are from their son and are his last words before Zimmerman shot him in the chest.

Circuit Judge Debra S. Nelson had heard three days of testimony about the science used by the state's experts. On Saturday she ruled that it failed to meet Florida's legal standard.

Jurors can expect prosecutors to still play the audio. They'll also likely hear testimony from Trayvon's mother and perhaps father that the screams came from their son. Zimmerman's father, Robert Zimmerman Sr., has testified that the voice is his son's.

Trial testimony is to begin Monday.

One of the state's experts, Alan R. Reich, had concluded the voice he identified as Trayvon is heard yelling, "I'm begging you," and "stop." The other, Tom Owen, ruled Zimmerman out as the screamer, in part, after using voice-recognition software.

Both witnesses are now banned from Zimmerman's trial, which began two weeks ago with jury selection.

The judge barred both experts, she wrote, because prosecutors failed to present competent evidence that the techniques used by Reich and Owen were generally accepted in the scientific field.

The state presented no evidence except Reich and Owen themselves, who defended their findings, she wrote.

She gave special attention to Reich. None of the five other experts who testified heard the words and phrases that he did, she wrote.

His testimony, she wrote, "would confuse issues, mislead the jury and, therefore, should be excluded from trial."

The recording is that of a neighbor who had called 911 to report the fight. The screams and gunshot can be heard in the background.

Four defense experts had challenged Reich's and Owen's findings, testifying that using screams to identify someone's voice is impossible. Valid voice comparisons can only be made if someone is speaking in a normal voice, they said.

The judge noted that three of the defense experts, including FBI analyst Hirotaka Nakasone, said they were "disturbed" by the state experts' conclusions.